Leases - Schedule of Maturities of Lease Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Operating Leases
Remaining three months of 2019	$ 191
2020	150
2021	118
2022	92
2023	72
Thereafter	266
Total lease payments	889
Less: Interest	97
Total lease obligations	792
Finance Leases
Remaining three months of 2019	3
2020	2
2021	2
2022	2
2023	1
Total lease payments	13
Less: Interest	2
Thereafter	3
Finance lease liability	$ 11
Operating Leases
2019		$ 207
2020		157
2021		116
2022		93
2023		76
Thereafter		244
Capital Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2019		3
2020		3
2021		1
2022		1
2023		1
Beyond 2023		$ 3